1) Field of the Invention
The present invention relates to a cell-image analyzing apparatus for automatically analyzing a collective of clustered cells (i.e. cell colony) using cell images.
2) Description of the Related Art
Analysis of a cell colony is conducted normally for observing cells as cultured. As an apparatus for conducting analysis of a cell colony, there is conventional one, for example, referred to in the operation manual “Analysis Software Operation, CELAVIEW RS100”, ver. 1.4, pp. 3-17, published by Olympus Corporation.
When special cells such as stem cells or ordinary cancer cells are cultured, the cells divide and grow. In such a situation, cells often cluster to form a colony. Therefore, automatic analyses of colonies are very frequently needed.
Cell analyses intended for colonies as subjects include various types such as those to determine whether cultured cells form a colony or not, dimensions of a colony, growth speed of a colony, etc. Upon analyzing such information on colonies, a screening, for example, of agents that promote or inhibit growth is made. Since a large number of samples and cell images are required for screening of agents in either cell analysis, it is necessary to automatically conduct the analysis of colonies.
A problem peculiar to colony analysis is in that, in a situation where a cell collective that forms a colony and cells other than those exist close to each other, it is necessary to distinguish the cell collective that forms a colony from the remaining cells. For example, there are some situations where some cells, out of cultured cells, form a colony and the remaining cells independently exist without forming a colony. Regarding stem cells, in particular, immature or undifferentiated cells form a colony while mature or differentiated cells independently exist without forming a colony. In such a case, a cell collective that forms a colony should be distinguished from mature or differentiated cells which independently exist.
As another example, there is a situation where plural kinds of cells coexist and only one kind of the cells form a colony.
As still another example, there is a situation where cells called “feeder cells” are simultaneously cultured with subject cells, for promoting growth of the subject cells or keeping alive the subject cells. In this case, it is necessary to distinguish the cell regions forming a colony, as the subject, and the remaining cell regions including the feeder cells.